1. Field of the Invention
The invention relates to a print system comprising: a host computer for forming print data in accordance with an instruction from the user; and a printer for forming image data by processing the print data transmitted from the host computer via a predetermined communication medium and actually printing it into a media such as a paper or the like.
2. Related Background Art
Hitherto, in a print system comprising a host computer and a printer, it is required not only that the printer prints on the basis of print data which is formed by the host computer but also that the getting of information of the printer and the setting of an environment thereof can be performed by the host computer.
Particularly, owing to the widespread implementation of networks in the printing environment, it has become popular to allow a plurality of users to share one printer having a high print processing speed and advanced functions via a network. This satisfies the need for large capacity printing in an office while minimizing management costs. Under such a situation, an administrator naturally wants to manage the printer in a real-time manner from some remote location without having to actually visit the printer. In addition, a user generally desires to perform secondary operations such as confirmation or cancellation of a processing situation of a print job issued by the user.
Many print systems which satisfy those requests have been considered.
FIG. 1 shows an example of such a print system which satisfies the above requests and is a block diagram showing a functional construction of the print system embodying a mechanism for transmitting a print job from the host computer to a printer, getting information of the printer, and setting an environment thereof. In the print system, a host computer 100 and a printer 150 are connected via a predetermined print medium 180.
The host computer 100 comprises: an application 101; a printer driver 102; a transmission buffer 103; an I/F driver 104; a utility 105; a logic channel controller 106; and a job packet generator 107.
The application 101 provides a graphical user interface to the user and forms image data according to an object of the user. The printer driver 102 converts the image data formed by the application 101 into page description language (hereinafter, abbreviated to PDL) data which can be printed by the printer 150. The transmission buffer 103 temporarily stores the PDL data formed by the printer driver 102. The job packet generator 107 adds job information of a print job which the application 101 possesses to the PDL data stored in the transmission buffer 103, thereby generating a job packet in accordance with a predetermined format.
The utility 105 obtains the information regarding the printer 150, provides a graphic user interface, and forms a management packet for setting information of apparatuses in the printer 150 in accordance with demands of the user and the administrator. The utility 105 also forms a management packet for requesting to obtain or cancel a status of the print job.
The logic channel controller 106 controls multiplication of the job packet formed by the job packet generator 107 and the management packet formed by the utility 105 and has a role as a transport layer in the OSI (Open Systems Interconnection) 7 layer. The I/F (Interface) driver 104 performs the transmission of the data generated from the logic channel controller 106 and the reception of the data transmitted from the printer 150.
The printer 150 comprises: a logic channel controller 151; a database 152; a job pre-processor 153; a reception buffer 154; a PDL translator 155; a draw buffer 156; a drawer 157; a printer engine 158; an I/F driver 159; an information manager 160; and an operation panel 161.
The I/F driver 159 receives the data transmitted from the host computer 100 and transmits the data formed by the logic channel controller 151. The logic channel controller 151 analyzes the data received by the I/F driver 159, attributes the job packet to the job pre-processor 153, distributes the management packet to the information manager 160, and contrarily transmits the management packet transmitted from the information manager 160 to the I/F driver 159.
The job pre-processor 153 receives and interprets the job packet, sends the PDL data to the reception buffer 154, and sends the job information of the job to the database 152.
The PDL data has been stored in the reception buffer 154 in receiving order. The job information such as the number of copies and the like and information regarding the apparatuses has been stored in the database 152.
The PDL translator 155 executes a translating process on the basis of the PDL data stored in the reception buffer 154 and the job information stored in the database, converts the PDL data into intermediate data which can be drawn by the drawer 157 in a real-time manner, and transmits the intermediate data to the draw buffer 156.
The draw buffer 156 stores the intermediate data of a plurality of pages and sends it to the drawer 157. The drawer 157 obtains the intermediate data from the draw buffer 156, performs a rendering of the intermediate data in a real-time manner in association with the paper conveying process which is performed by the printer engine 158, and transmits video data to the printer engine 158. The printer engine 158 physically prints an image onto a paper on the basis of the video data transmitted from the drawer 157 by using the well-known electrophotographic technique.
The information manager 160 receives an information obtaining request from the utility 105 in a form of the management packet, obtains the necessary information from the database 152, converts it into a management packet, and replies to the host computer via the logic channel controller 151. The information manager 160 detects the end of the job, autonomously converts an end notice of the job into a management packet, and sends it to the host computer.
The operation panel 161 is equipped for the main body of the printer 150 and comprises a display apparatus such as liquid crystal, LED, or the like and operation buttons. The operation panel 161 executes a process for reflecting the input (setting) from the user to the database via the information manager or displaying the present status of the apparatus.
Processes in the case where the printer 150 receives a print request of the print job will now be described. When the printer 150 receives the print request of the print job, the job pre-processor 153 recognizes this new print job and allocates a job ID which is unconditionally held in the printer to this print job. Such information is stored in the database 152. The information is deleted at a stage when all pages of the print job are interpreted and drawn and it is detected in the printer engine 158 that the paper ejection of the last one page has been completed.
A mechanism of the function to cancel the job in the print system will now be described.
The job cancelling function is a function for requesting a cancellation of the print of the print job transmitted to the printer from the user or administrator who issued the print request. The user or administrator requests the cancellation from the user interface of the utility 105 or from the operation panel 161.
The utility 105 issues a management packet to request the getting of a job list in the apparatus to the printer 150. The printer 150 transmits a list of the job IDs of all of the print jobs recognized in the apparatus. The utility 105 receives the job ID list and displays statuses of the print jobs in the apparatus by using the graphic user interface.
When the user who transmitted the print job or the administrator of the printer selects a certain print job among the displayed print jobs and requests the cancellation of the selected print job, namely, when the job ID of the print job whose printing is cancelled is designated by the graphic user interface of the utility 105, a management packet of a job cancel request is formed and transmitted to the printer 150. When the management packet of the job cancel request is transmitted to the printer 150, the information manager 160 detects it. When the PDL data or intermediate data regarding the print job exists on a print path, specifically speaking, on the reception buffer 154, PDL translator 155, draw buffer 156, and drawer 157, an invalidation, a deletion, an erasure, or the like of those data or an interruption of the processes of those data is performed.
In case of cancelling the job from the operation panel 161, it is difficult to clearly designate the job ID. Therefore, the print job whose process has been progressed most on the print path is set to a target for cancellation. Specifically speaking, when the job is processed by the printer engine 158, this job is set to a target for cancellation. In another case, the job that is being processed in the drawer 157 becomes a target. In still another case, the job that is being processed in the PDL translator 155 becomes a target. In this manner, when the job under processing is found on the print path, the job ID of such a job is set to a target for cancellation and the job ID of the relevant job is specified.
The actual cancelling process of the job by the operation panel in the printer is substantially the same as that by the utility 105 except for a point that a deciding method of the job as a target for cancellation differs. By the above operations, an arbitrary job in the printer 150 can be cancelled.